Wastewater lift stations, also referred to as pumping stations, are facilities employed by municipalities to transfer wastewater. In a conventional system, transfer of wastewater is from a lower elevation to a higher elevation, wherein gravity allows further wastewater fluid flow. However, in certain instances, the elevation of the source is not sufficient to gravity flow, and a lift station essentially operates as a transfer station.
Lift stations are used to reduce the capital cost of sewer system construction. The lift stations allow the municipality to avoid digging deep trenches, so as to allow gravity flow. Deep trenches are expensive to install, mainly due to the costly excavation and trench wall shoring issues. Further, lift stations allow use of a reduced pipeline size, wherein pump transfer provides an adjustable and sustainable pipeline flow rate.
The main elements of a lift station are the wastewater receiving well and the associated pump. The wastewater receiving well receives waste from one source, where it is held temporarily for transfer to another location by use of the pump. The receiving well requires a ventilation system, so as to allow the displacement of air during the filling of the receiving well, as well as incoming air required during the emptying of the receiving well. During operation, the wastewater contains certain bacteria that grow and mutate, resulting in odors that can be quantified as slight to outright annoying. For this reason, a vent is placed on the receiving well, so as to treat the displaced air while the receiving well is being filled, and allow air intake into the receiving well while it is being emptied.
The odor emanating from the receiving well is commonly treated by the use of an activated carbon vent, which is known to absorb unpleasant odors and gases using activated carbon material. The activated carbon material consists of a specially treated charcoal that has been oxygenated at a high pressure to create hundreds of thousands of pores on the surface. In this manner, the activated carbon acts like a sponge to absorb peculiar gases and odors. The longevity of the activated carbon is dependent upon the pores that are being filled with the objectionable matter. Once filled, the activated carbon can either be disposed of, or re-fired for additional activation. Unfortunately, the cost of the activated carbon can be expensive, and the exchanging of the activated carbon is not necessarily a pleasant task.
Air scrubbers are known in the industry for removing odors using a liquid to wash unwanted pollutants from a gas stream. However, such devices are costly, require close maintenance and consume a large footprint, making them an unsightly addition to a lift station, especially those found in residential areas.
Thus, what is needed in the industry is a passive venting device that requires a small footprint and is capable of replacing foul odors expelled from a wastewater receiver lift station with a pleasant scent.